1. Field of the Invention
The present invention relates to an information processing device, a non-transitory computer-readable recording medium storing an information processing program, and an information processing method which allow for information input using a gesture operation.
2. Description of Related Art
In recent years, information processing devices provided with a touch panel, in which information can be input by directly touching the screen with a contact member such as fingers and a stylus as with smartphones, tablet terminals, or electronic whiteboards have been practically used. When a predetermined gesture operation is performed on the touch panel of the above-mentioned information processing devices, a process assigned to the gesture operation (for example, movement of an object and the like) is executed.
A gesture operation of touching one point on the touch panel is called single touch gesture, and a gesture operation of simultaneously touching two or more points on the touch panel is called multiple touch gesture. In recent years, the progresses of the multiple touch gesture technology have made it possible to perform diversified and complicated operations.
Examples of the gesture operation include pinch-out which is an operation of enlarging an object by touching and sliding two points on the object in such a manner as to move the touch points away from each other, pinch-in which is an operation of reducing the size of an object by touching and sliding two points on the object in such a manner as to bring the touch points close to each other, and the like. In the following description, pinch-out and pinch-in are referred also to as “resizing.” It is to be noted that resizing includes, in addition to enlarging/reducing of an object to a similar shape in longitudinal and lateral directions, enlarging/reducing of an object in only a vertical direction or in only a lateral direction.
In conventional information processing devices provided with a touch panel, the expansion-reduction rate of resizing is set in advance, and an object is enlarged or reduced by an amount corresponding to the operation amount [pixel] (change of the distance between two touch points)×the expansion-reduction rate. For example, when the expansion-reduction rate is set to 1.5, an object is enlarged or reduced by an amount corresponding to the operation amount×1.5 [pixel]. When the expansion-reduction rate is set to 1, an object is enlarged or reduced by the operation amount to follow the motion of the finger.
Conventionally, PTL 1 (Japanese Patent Application Laid-Open No. 2012-121179) discloses, as a technique relating to resizing, an image forming apparatus provided with a preview function in which an object is enlarged or reduced to a standard-size size when the operation speed of the resizing, that is, the change speed of the distance between two touch points (hereinafter referred to as “point distance change speed”) is equal to or greater than a threshold value, for example.
Incidentally, large touch panels such as electronic whiteboards display an object having a size larger than that of small touch panels such as mobile terminals, and therefore multiple touch gestures using both hands are likely to be performed on the large touch panels. When resizing is performed by two-hand operations, the movable range of hands is large, and therefore the operation amount tends to be increased in comparison with resizing performed by one-hand operations (see FIGS. 1A and 1B).
However, as with the image forming apparatus disclosed in PTL 1, in the case where the expansion-reduction rate for resizing of the object is set to, for example, a constant value without taking into consideration whether the operation is the one-hand operation or the two-hand operation, an operation which is not intended by the user may be reflected on the screen. Illustratively, in the case where the expansion-reduction rate is set to a large value (large difference from 1) on the assumption that resizing is performed by one-hand operations, the object may be excessively enlarged or reduced when resizing is performed by two-hand operations. On the other hand, in the case where the expansion-reduction rate is set to a small value (small difference from 1) on the assumption that resizing is performed by two-hand operations, the gesture operations may have to be repeatedly performed when resizing is performed by one-hand operations.